The invention relates to a shaver comprising a skin-support element, a first blade, and a second blade which, viewed in a cutting direction of the blades, follows the first blade, said blades being provided with substantially parallel cutting edges extending perpendicularly to the cutting direction and substantially in a hair cutting plane touching the skin-support element.
The invention also relates to a shaving head which can suitably be used in a shaver in accordance with the invention.
A shaver of the type mentioned in the opening paragraph is known from EP-A-0 559 130. The known shaver is a wet shaver in which both blades are fitted in substantially fixed positions in a shaving head which is detachably secured to a holder of the shaver. To shave hairs, the known shaver has to be placed on the skin, the skin touching the skin-support element and the two blades, and the shaver has to be moved over the skin in the cutting direction. As a result, hairs near the hair cutting plane of the shaver, i.e. directly above the surface of the skin, are severed by the blades, resulting in a fairly smooth shaving result.
A drawback of the known shaver is that the shaving result attained lasts only a relatively short period of time. This drawback can be attributed to the fact that hairs severed by means of the known shaver relatively rapidly grow beyond the surface of the skin again.
It is an object of the invention to provide a shaver of the type mentioned in the opening paragraph, in which the above-mentioned drawback is precluded as much as possible, so that an attained shaving result lasts a longer period of time.
To achieve this, the shaver in accordance with the invention is characterized in that the first blade is provided with a blocking element which is provided on a side face of the first blade at a distance from the cutting edge of the first blade which is substantially smaller than an average diameter of hairs to be shaved by means of the shaver, while the first blade can be periodically moved by means of a drive unit substantially in the cutting direction from a first position, in which the cutting edge of the first blade is situated close to the cutting edge of the second blade, to a second position. By applying said blocking element on the first blade, the shaver in accordance with the invention obtains a so-called retractile action, as will be explained hereinbelow. If the shaver in accordance with the invention is moved over the skin in the cutting direction, a hair to be severed is first reached by the cutting edge of the first blade. Since the first blade is provided with said blocking element, the cutting edge of the first blade penetrates the hair only over a distance which corresponds to the distance between the cutting edge of the first blade and the blocking element, which distance, consequently, is substantially smaller than the diameter of the hair. A further penetration of the cutting edge of the first blade into said hair is precluded by the blocking element because the blocking element cannot penetrate into the hair. As the first blade is subsequently moved by means of the drive unit in the cutting direction from the first position to the second position, said hair is pulled along by the first blade in the cutting direction and hence partly extracted from the skin. Subsequently, the hair thus partly extracted from the skin is severed by the second blade directly above the surface of the skin, whereafter the hair is finally retracted into the skin by the skin tissue present around the hair shaft. As a result, the severed hair sinks back below the surface of the skin, so that not only a very smooth shaving result is obtained but, in addition, the shaving result thus obtained is maintained for a longer period of time because the severed hair does not directly grow beyond the surface of the skin. It is noted that the above-mentioned distance over which the cutting edge of the first blade penetrates the hairs should be such that the hairs can be pulled along by the first blade, but are not severed by said first blade. It has been found that, to achieve this, the distance between the cutting edge of the first blade and the blocking element must be substantially smaller than an average diameter of the hairs to be shaved by means of the shaver.
A particular embodiment of a shaver in accordance with the invention is characterized in that the distance between the cutting edge of the first blade and the blocking element ranges between 10 xcexcm and 50 xcexcm. As a result, the shaver in accordance with the invention can particularly suitably be used to attain a smooth, longer-lasting shaving result when shaving off beard hairs, which customarily have an average diameter of approximately 100 xcexcm.
A further embodiment of a shaver in accordance with the invention is characterized in that the distance between the cutting edge of the first blade and the blocking element is substantially 30 xcexcm. It has been found that, by virtue thereof, the shaver in accordance with the invention has a substantially optimum retractile action during shaving beard hairs.
Yet another embodiment of a shaver in accordance with the invention is characterized in that the blocking element is provided on a side face of the first blade facing away from the second blade. By virtue thereof, it is achieved that the distance over which the cutting edge of the first blade penetrates into the hairs substantially does not deviate from the distance between the cutting edge of the first blade and the blocking element, so that a reliable operation of the shaver is attained.
A particular embodiment of a shaver in accordance with the invention is characterized in that the first blade comprises a carrier on which a blade part including the cutting edge of the first blade is secured, the blocking element being a front side of the carrier extending transversely to the side face of the first blade. By virtue thereof, a simple and practical construction of the shaver in accordance with the invention and the blocking element applied therein is achieved.
A further embodiment of a shaver in accordance with the invention is characterized in that the shaver is provided, near the hair cutting plane, with a guide extending substantially parallel to the cutting direction, along which guide the first blade is guided during displacements from the first position to the second position. By using said guide, the first blade is accurately guided in the cutting direction during displacements from the first position to the second position. By virtue thereof, skin lesions are precluded as much as possible.
Yet another embodiment of a shaver in accordance with the invention is characterized in that the guide comprises at least one strip which extends substantially parallel to the cutting direction, which strip is formed by incisions in the second blade and is bent from said second blade. In this manner, a particularly simple and practical construction of the shaver in accordance with the invention is obtained.
A particular embodiment of a shaver in accordance with the invention is characterized in that the drive unit is provided with a coupling member which can be oscillated, through a limited angle, about a first pivot axis, while the first blade is displaceably guided in a guide channel of the shaver, which channel extends obliquely with respect to the hair cutting plane, the first blade being pivotable, through limited angles, in the guide channel about a second pivot axis extending parallel to the first pivot axis, the first blade being provided with at least one hinge element which can be hinged in a hinge channel of the coupling member extending parallel to the first pivot axis, and which hinge element can be displaced in the hinge channel in a direction transverse to the hair cutting plane. In this embodiment of the shaver in accordance with the invention, the cutting edge of the first blade is periodically displaced with respect to the second blade by means of the drive unit so as to follow an approximately triangular or quadrangular path. Said path comprises a first path part directed parallel to the cutting direction and extending from the first position to the second position, and a second path part directed obliquely with respect to the cutting direction and extending from the second position to a third position, wherein the first blade is situated behind the second blade, viewed with respect to the hair cutting plane.
A further embodiment of a shaver in accordance with the invention is characterized in that the second pivot axis is determined by lugs, which are formed by incisions in the first blade and are bent from the first blade, the first blade also being displaceably guided in the guide channel by means of said lugs. In this manner, a very simple and practical construction of the shaver is obtained.
Yet another embodiment of a shaver in accordance with the invention is characterized in that the skin-support element and the two blades form part of a shaving head of the shaver, which shaving head is detachably secured to a holder of the shaver, the drive unit being situated in the holder and being detachably coupled to the first blade. If, after repeated use of the shaver, the blades have become blunt, said blades can be readily replaced by substituting the shaving head with a new shaving head.
A particular embodiment of a shaver in accordance with the invention is characterized in that the shaving head is provided with a coupling guide extending parallel to the two pivot axes, which coupling guide serves to co-operate with a further coupling guide of the holder, the shaving head being detachable from the holder by sliding both coupling guides apart in a direction parallel to both pivot axes, the first blade simultaneously being detachable from the drive unit by sliding the hinge element of the first blade out of the hinge channel of the coupling member in a direction parallel to the two pivot axes. In this manner, a particularly simple and practical coupling between the shaving head and the holder, and between the first blade and the drive unit, is obtained.